Bill H. Hoyer

Evolution of primate DNA sequences

Abstract This study is concerned with comparing the DNA sequences of different mammals, mainly primates, by utilizing nucleic acid hybridization. Nucleotide sequence differences between different species have been quantitated. Rates of nucleotide sequence change have been calculated. These data suggest that nucleotide sequence change has been decreasing with the development of the primate line. They also indicate that the rate of nucleotide sequence change in Primates is 10 – 20 × lower than that for rodents during recent evolutionary times. When corrected for generation time the rodent and primate rates are essentially equal.

Examination of hominid evolution by DNA sequence homology

Abstract Hominoid phylogeny was investigated in terms of unique DNA sequence homologies. In comparisons from the human standpoint the ΔTe 50 DNA values were Man 0, chimpanzee 0·7, gorilla 1·4, gibbon 2·7, orangutan 2·9, and African green monkey 5·7. In comparisons from the orangutan standpoint the ΔTe 50 DNA values were orangutan 0, chimpanzee 1·8, Man 1·9, gorilla 2·3, gibbon 2·4 and African green monkey 4·3. These results indicate that chimpanzee and gorilla are cladistically closer to Man than to orangutan and other primates, and that gorilla DNA may have diverged slightly more from the ancestral state than chimpanzee or human DNA. Comparisons from chimpanzee and gorilla DNA standpoints are needed to achieve a more definitive picture of hominoid phylogeny.

Mammalian Viruses and Rickettsiae Their purification and recovery by cellulose anion exchange columns has significant implications.

Techniques of column chromatography with cellulose ion exchangers have been successfully applied to mammalian viruses and rickettsiae. Recovery of virus is excellent, and appreciable purification in terms of phosphorus and protein removal has been demonstrated. Elution characteristics of poliovirus (types 1, 2, and 3), and Coxsackie A9 virus are similar, whereas those of ECHO-13 and Colorado tick fever differ from them as well as from each other. Elution diagrams of preparations of ECHO-13 and polio 2 viruses grown on P32-labeled tissue cultures show a high degree of correlation between the distribution of titratable virus and the distribution of radioactivity. A single adsorption and elution of Q fever or epidemic typhus fever rickettsiae results in a striking degree of purification, as demonstrated by electron micrographs. The chromatographic behavior of the animal viruses and rickettsiae appears to depend more upon the chemical nature of the surfaces of these infectious agents than upon their size. The chromatographic procedure described may prove useful in the preparation of purified, P32-labeled, fully infectious animal viruses for further fundamental research. It may also prove useful for the removal of unwanted host materials in the preparation of vaccines.

The Evolution of Polynucleotides

Publisher Summary This chapter discusses the evolution of polynucleotides. Comparisons of amino acid sequences, enzymatic activities, and immunological properties of macromolecules shows only a few of the many attributes of the organisms under consideration. Specific affinities observable among various DNA are indicative of qualities of the whole organism. This chapter presents the findings that are restricted to the DNA–DNA relationships among vertebrates with emphasis on the primate group. The primates were chosen for the present study because of the interest in their relationships and because of the backlog of information concerning this group from a variety of studies that range from the molecular to the sociological. The implications of the data presented for understanding the mechanism of organic evolution urge the experiments that can distinguish between the alternative interpretations of evolutionary divergence or assess their relative importance, should they both be applicable.